The Renault R3 is a budget version of the Renault 4 supermini, produced in 1961 and 1962. The difference between the two cars was that the Renault 3 had a smaller 603 cc engine.
Sales of the Renault 3 were poor because the larger engined Renault 4 was priced in 1961 at less than 4% more. Given the very close similarity between the R3's 603 cc and the R4's 747 cc engine blocks, even this difference probably exaggerated any difference in manufacturing costs.
Initially the basic R3 and the basic R4 both came without a third side window, hubcaps, a screen washer or interior door linings: bumper bars and grill were painted in the body colour, at that time was considered very mean, but which avoided the cost of chrome plating.
When the R3 was withdrawn in October 1962 Renault also withdrew the very basic stripped down version of the R4, and from this date all saloon-bodied Renault R4s came with a third window on each side.